A new kind of rotor damper,Ring-like Metal Rubber Damper(RMRD),has been invented.Its application to a rotor rig shows that RMRD has excellent damping property and linear characteristics.RMRD has better damping effects and can withstand larger unbalanced load than Squeezed Film Damper.As a kind of dry-friction damper,RMRD can work under very high or low temperature for a long period of time.It is especially suitable for High Pressure Liquid Hydrogen(Oxygen) Pumps of rocket engines working under very low temperature.